CVE-2017-18017 Use after free in n/a

Critical 9.8 Published 3 Jan 2018 Updated 3 Jan 2025

Remote attackers can trigger a use-after-free in the Linux kernel TCPMSS module, causing denial of service or potential code execution.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2017-18017?

CVE-2017-18017 is a critical use after free vulnerability in Canonical Ubuntu Linux, published on 3 Jan 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The tcpmss_mangle_packet function in net/netfilter/xt_TCPMSS.c in the Linux kernel before 4.11, and 4.9.x before 4.9.36, allows remote attackers to cause a denial of service (use-after-free and memory corruption) or possibly have unspecified other impact by leveraging the presence of xt_TCPMSS in an iptables action.

Weakness: CWE-416

Which versions are affected by CVE-2017-18017?

It affects 29 products.

Products include Arista Eos, Canonical Ubuntu Linux, Debian Debian Linux, F5 Arx, Linux kernel, Openstack Cloud Magnum Orchestration and 23 more.

How do I fix CVE-2017-18017?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2017-18017 being exploited?

There is no known exploitation of CVE-2017-18017 in the wild and no public exploit code.

All Canonical Ubuntu Linux vulnerabilities

Sources

Also known as DEBIAN-CVE-2017-18017, GHSA-3fj5-q6p4-25m2, UBUNTU-CVE-2017-18017.